Heating method and apparatus



F. PUENING HEATING METHOD AND APPARATUS June 23,

4 SheetsSheet I 1 Filed Jan. 18, 1923 I/JNVEN'FOLR 2M "lilllilillrkliu lnn Pu huhhfiul v 1 rlur June 23, 1925.

F. PUENING HEATING METHOD AND APPARATUS 4 Sheets- Sheet 2 INVENTOR Filed 'Jan. 18, 1925 A. 7 h m 2 7%. "I

June 23, 1925. 1,542,955

F. PUENING HEATING METHOD AND APPARATUS Filed Jan. 18, 1923 4 Sheets-Sheet 5 June 23, 1925. 7 1,542,955

F. PUENING HEATING METHOD AND APPARATUS Filed Jan. 18, 1925 4 Sheets-Sheet 4 Patented June 23, 1925.

PATENT-- OFFICE.

FRANZ PUENING, OF ASPINWALL, PENNSYLVANIA.

HEATING METHOD AND ABPARATUS.

Application fil ed. January 18, 1923. Serial No. 618,396.

To all whom it may concern:

Be it known that I, FRANZ PUENING, a citizen of the-United States, and resident of Aspinwall, in the county of Allegheny and State of Pennsylvania, have invented a new and useful Improvement in Heating -Methods and Apparatus; and I do hereby declare the following to be a full, clear, and exact description thereof.

My invention relates to apparatus or furnaces for heating retorts, chambers, leers,

and any other objects where it is necessary that the heat be closely regulated, maintained uniform, and kept below the temperature of combustion of ordinary fuel. In particular, my present invention aims to provide improved apparatus for carrying out a method of heating described and claimed in my copending applications for Letters Patent filed July 16, 1920, Serial No. 396,693, and filed December 8, 1922, Serial No. 606,037.

In my prior applications I have disclosed heating methods which involve the use of mechanical means for forcing combustion products or other heated gases through the space to be heated and for rapidly reversing the flow of such gases, thereby causing the heat to be communicated to the articles with in the furnace or other enclosure in -a uni,- form manner and at a temperature level below the temperature of combustion of the average fuel. Where gases of combustion are used as the heating medium, a portion of these gases, which has given up most of its heat, is discharged from the system at each reciprocation of the gases and is replaced by a fresh portion of combustionout the method outlined above, and dcscribed in greater detail in my prior applications, by means of an'impelling member or piston which oscillates around a fixed pivot within a chamber which is preferably disposed parallel to the heating chamber or other body to be heated, and which communicates with that chamber through suitable ports. I also provide improved means for heating, distributing and releasing the circulating gases and thus obtain a furnace which is particularly useful for the heating of long objects. I 1

In the accompanying drawing, Fig. 1 is a plan view, with parts in section on the line 11, Fig. 4, showing a furnace provided with heating apparatus constructed in ac cordance with my invention; Fig. 2 is a longitudinal vertical section with parts broken away, of the apparatus of Figs. 1 and 4; Fig. 3 is an end view of the same apparatus as seen-from the right of Figs. 1 and 2; Fig. 4 is a transverse vertical sectional View, the section being taken substantially on the line 4-4, Fig. 1; Fig. 5 is a longitudinal sectional view showing a modified way in which the heat-sources may be arranged, the section being taken substantially on the line 5-5, Fig. 6; Fig. 6 is a transverse vertical sectional view of the construction shown in Fig. 5, the section being taken substantially on the line 66, Fig. 5; Fig. 7 is a longitudinal sectional View taken substantially on the line 77, Fig. 8, showing the-manner in which theapparatus may be arranged as a mufllefurnace; and Fig. 8 is a transverse vertical sectional view of the construction shown in Fig. 7, the section being taken substantially on the line 88, Fig. 7-.

an enclosure to be heated consisting in this instance of an elongated heating chamber.

having any desired dimensions. For example, the heating chamber 2 may be twenty or thirty feet long and five or six feet wide. It will be understood that the heating chamber here shown is merely illustrative, and that the heating zone may be of any other size or shape. As shown, the chamber 2 is provided with doors 3 at its ends, and with a removable cover4: having suitable means for lifting and transporting it, such as eyeplates 5 and chains 6.

Below the floor 7 of the heating chamber 2 is a space 8 having a circularly, curved lower wall 9 and communicating with the heating chamber 2 through vertical ports 10 which are located at the sides of the heating chamber 2. The walls of the heating chamrents in the furnace chamber.

ber 2 and of the auxiliary space 8 may suitably be composed of fire-brick and may be supported upon a masonry or concrete foundation 11.

Mounted for oscillation upon suitable bearings at opposite ends of the furnace is a hollow horizontal shaft 15 which extends lengthwise through the auxiliary space 8 a short distance below the floor 7 of the chamber 2. The hollow shaft 15 carries a swinging oscillator 16 which sweeps through the space 8 and operates to drive the air or other gases alternately through the vertical passages 10 on the opposite sides of the furnace, thus setting up alternating gas cur- As shown, tuis oscillator 16 is composed of side plates 27, end plates 18 and intermediate stiffening plates 19 forming a box-like structure, the hollow shaft and the intermediate plates 19 being perforated to permit the passage of a cooling medium as, for instance, air which is drawn through the hollow shaft 15 in the manner described below. The sides of the oscillator 16 may, as shown, be covered with insulating sheet material 20, and the ends of the oscillator may also be covered with insulating material, if desired, as shown at 21.

For the purpose of providing a seal to prevent the gases in the chamber 8 from passing around the upper end of the oscillator 16 when the oscillator is in operation, I provide a sealing member 23 which, as best shown in Fig. 4, consists of a curved plate resting upon the hollow shaft 15 and having a curved end 24 which is received in a hooked bracket 25 that is secured beneath the floor 7 of the furnace 2 by suitable anchor bolts 25. The sealing member 23 offers substantially no resistance to the movement of the shaft 15 and the oscillator 16, but prevents the- \passage of gases above the shaft 15.

The oscillator 16 and the sealing member 23 may each be made in a single unit extending the full length of the chamber 8, but for installations where this chamber must be very long it is preferable to divide the oscillator 16 and the sealing member 23 into sections for convenient assembly and replacement.

Mechanism for oscillating the shaft 15 and the oscillator 16 is shown on Figs. 1, 2 and 3, and consists of a crank 26 secured to one end of the hollow shaft 15, a pin 27 carried by the crank 26, a connecting rod 28, and a pin 29 carried by a crank 30 which is secured to a shaft 31 driven by an electric motor 32 through a suitable coupling 33 and a set of reduction gearing 34.

The heating chamber 2 may be heated either by direct introduction of hot gases of combustion or in the manner of a mufile furnace, where the gases of combustion do burners as is desirable when oil is the fuel,

and Figs. 7 and 8 show a construction which may be employed for operating the furnace as a mufile apparatus.

Referring first to the heating arrangements shown on Figs. 1 to 4, combustion chambers 38 are formed in the side walls of the furnace beneath its floor level and communicate laterally withthe vertical passages 10. The combustion chambers 38 are provided with individual burners 39 supplied with gas or other fuel through pipes 40 controlled by valves 41. Air is supplied to the burners 39 through pipes 42, and the air supply to each burner is controlled by means of a valve 43.

When the oscillator 16 swings from left to right, as shown in Fig. 4, it drives ahead of it the gases in the chamber 8 which are forced up through the vertical passages 10 at the right side of the furnace. While passing through these passages, new hot combustion gases are added from two sides to each stream passing through each passage. At the same time the gases in the chamber are drawn into the auxiliary chamber on the left side 'of the piston, through the passages 10 at the left hand of the chamber, the burners at the left hand adding hot gases to these gases as they pass downward.

Since the burners continuously add gases of combustion to the reciprocated old gases, a portion of'the gases in the system must be removed at each movement of the oscillator. For this purpose I provide outlet ports and 46 in the side walls of the furnace and these are evenly distributed over the whole length of the heating chamber and are provided with adjustable dampers 47 for regu lating the outflow of gases of combustion.

The outlet ports 45 and 46 communicate respectively with chambers 48 and 49 which are formed in the side walls of the furnace and extend substantially the full length thereof. At one end of the furnace, as shown at the right of Fig. 1, the chambers 48 and 49 communicate through horizontal passages 50 and 51, respectively, with chimney pipes 52 and 53 provided with swinging dampers 54 and 55 having operating levers 56 and 57, respectively.

Referring again to Fig. 4, and assuming as above that the oscillator is moved from left to right, it is evident that all the hot gases forced up through the. right hand passages 10 should be forced to cross the heating chamber 2before any part of them leaves the heating chamber. During this stroke of the piston the swinging damper 54 at the right hand side of the chamber is closed and that at the left is open to permit the escape of the .waste gases. Similarly when the oscillator reverses its movement and travels from right to left, Fig. 4, the left hand damper 55 is closed and the right hand damper 54 is open. For this purpose I provide automatic means for operating the.

dampers 54 and 55 at the beginning of each movement of the oscillator 16. This mechanism is shown on Figs. 1 and 3 and includes a disc 60 secured rigidly to the hollow shaft 15 and having a grooved periphery, a friction band 61 surrounding the disc 60, an arm 62 carried by the friction band 61 and extending upwardly and radially with respect to the disc 60, and rods 63 and 64 having their outer ends pivotally connected to the damper levers 56 and 57, respectively, and having their inner ends pivotally connected to the arm 62. As shown, the band 61 and the arm 62 are composed of two straps of metal having semi-circularly curved -portions forming the strap .61 and having straight portions forming the arm 62 and connected by means of bolts or rivets 65. The ends of the friction band 61 are connected by means of a bolt 66 and a compression spring 67 surrounds the bolt 66 and causes the friction band 61 to grip the disc 60 with a pressure which is regulated by means of a nut 68. Stops 69 and 70 are provided for limiting the swinging movement of the arm 62.

Figure 3 shows in full lines the position of the damper mechanism when the oscillator is at. the end of its swinging movement to the left in this figure, at which time the damper 54 in the pipe 52 is closed and the damper 55 in the pipe 53 is open. When the shaft 15 and the oscillator 16 begin to move in the opposite direction, the disk 60 which moves with the shaft 15 carries with it the friction band 61 and causes the arm 62 to rock to the left until its movement is arrested by the stop 70. This movement of the arm 62 operates through the rods 63 and 64 to swing the damper levers 56 and 57 to the left, thus opening the damper 54 and closing the damper 55. When the movement of the arm 62 is arrested by the stop 70, the disc 60 continues to rotate within the friction band 61 until the oscillator completes its swing to the right, Fig. 3, and when the oscillator again begins to move to the left the operation of the damper mechanism is reversed and the arts are restored to the position shown in'Fig. 3.

The longitudinal chambers 48 and 49 are utilized to preheat the air which is supplied to the burners 39, this air having previously end of the furnace and communicates. with pipes 79 and 80 which extend into the heatrecuperating chambers 48 and 49, respectively. The pipes in the two recuperating chambers are arranged similarly and in the manner illustrated in Fig. 2, where the pipe 80 is shown extending the full length of the recuperating chamber 49 near the top thereof, and communicating successively with pipes 81, 82 and 83 arranged one below the other in such a way that the air passes through the full length of the recuperating chamber four times. The outlet end of the pipe 83 is connected by means of elbows 84 and a nipple 85 to one end of one of the pipes 42 which supply air to the burners 39.

The furnace shown in Figs. 5, and 6 dif- 'fers from that of Figs. 1 to 4 only in the arrangement of the burners which supply gases of combustion to the furnace. Instead of having numerous combustion chambers 38 each provided with a burner 39, the furnace shown in Figs. 5 and 6 is provided withtwo combustion chambers only at each side of the furnace, these combustion chambers being shown at 90 and being provided with' burners 91. Vertical and upwardly flaring chambers 92 connect the combustion chambers 90 with horizontal passages 93 which correspond to the combustion chambers 38 in the furnace of Figs. 1 to 4, and which communicate with the vertical passages 10 that lead into the heating chamber 2.

The burner arrangement shown in Figs. 5 and 6 is preferable when oil is employed as fuel for the burners. When gas is available as the fuel, the arrangement ofindividual burners shown in Figs. 1 to 4 is preferable, as these burners ma be readily adjusted to give either a uni orm temperature throughout the full length of the furnace, or to divide the furnace into heating zones of different temperatures, as ma be. desired, this division of the heating 0 amber into zones being particularly useful when the articles to be heated are moved continuously through the heating chamber 2, as may readily be done by the arrangements ordinarily uspd in tunnel kilns, annealing leers and the li e.

Figures 7 and 8 show a modified arrangement in which the heating chamber 2 is operated as a muflle furnace. Horizontal heating pipes are arranged within the heating chamber and means are provided for circulating the gases of combustion through these pipes without entering the heating chamber 2. As shown, such pipes are provided on each side of the heating chamber, and these pipes are connected in pairs, with a burner for supplying combustion gases at one end of each pair. One pair of pipes is indicated at 95, while the other pair is shown at 96. A burner 97, supplied with fuel gas or oil, produces a flame at the inlet end of the pipe 95 and the gases of combustion from the pipe 95 are discharged through a vertical chimney 98 at the same end of the furnace as the burner 97. Similarly, a burner 99 produces a flame at the inlet end of the pipe 96, and the gases of combustion from the pipe 96 'are discharged through a vertical chimney 99*. The heating pipes just described may be arranged one above the other in each pair, as shown on the drawing, or may be arranged with the pipesin each pair side by side, if desired. It will be evident that heating pipes of this kind may readily be replaced by electric heating units.

When the apparatus is used as a muflie furnace it is not necessary to provide for removing gases from the heating chamber, and the same volume of air or other gas may be reciprocated continuously through the heating chamber by means of the oscillator.

In the operation of the apparatus de' scribed above, the oscillator 16 swings continuously and at suflicient speed to produce rapid alternations in the gas currents which flow through the heating chamber. At each movement of the oscillator the gases contained in the auxiliary chamber 8 are forced. up or down through the passages 10 entering into or returning from the heating chamber 2, and in the apparatus of Figs. 1 to 6 draw with them gases of combustion froln the burners. The gases so reciprocated through the heating chamber will be at a lower temperature than the temperature of combustion of the fuel. on account of the dilution of the gases of combustion by the gases forced from and returning into the auxiliary chamber 8. Likewise, the gases delivered into the heating chamber are of uniform temperature, since the oscillator 16 is of rectangular shape and therefore posseses the same volumetric displacement for each foot of its length, moving equal volumes of old used gases through the heating chamber. The gases forced into the heating chamber 2 are caused to move across the heating chamber, and they leave the heating chamber and reenter the auxiliary chamber through the passages 10, only a small portion of them leaving through the upper ports 45. The same action then occurs in the reverse direction, and this al-' ternate movement of the oscillator and of the heating gases continues throughout the heating operation, causing the articles within the chamber 2 to be heated in a uniform and controllable manner. Much of the waste heat is recovered from the discharged gases by the air drawn through the pipes in the recuperating chambers 48 and 49 preparatory to being delivered to the burners.

In order to aid in distributing the heating gases within the chamber 2, vertical walls 100 may be provided on opposite sides of the heating chamber as shown in Fig. 6. These walls have openings 101, of any desired number and arrangement, and pieces of brick 102 may be provided, if desired, to partiall close the openings 101 or to close some 0 these openings entirely. The flow of heating gases maybe regulated in this manner, so as to produce zones of different heat-intensity in the furnace chamber or to adjust the heating currents otherwise as may be required.

It will be observed that the oscillating piston swings like a natural pendulum and requires no outward energy to reverse its stroke and carry it past the vertical position.

But little power is therefore required for the piston operation, as compared with the power necessary to reciprocate a piston of similar capacity movable in a straight line. The end positions of the piston may be angularly displaced by any suitable angle less than 360 degrees.

The structural details herein shown and described may be varied in. many respects without departing from my invention, and this apparatus is intended for use in, heating any enclosure where uniform and regulable heat is desired. It is particularly useful where articles are to be heated at temperatures considerably below the combustion temperature of ordinary fuels, and where it is desired to avoid the local heating which occurs when flames or undiluted combustion gases are played directly upon the articles to be heated. Thus, for example, the apparatus may be employed with beneficial results inthe annealing of metal bars, sheets, and plates, in the low-temperature coking of coal, in annealing glassware, or in the cracking of hydrocarbons. In View of the many variations of which my invention is capable, both in construction and use, it is to be understood that no limitations are to be imposed upon my invention, except such as are indicated in the appended claims.

I claim as my invention:

1. In heating apparatus, the use of an oscillating member for moving heatinggases back and forth in a container to reduce local heat-intensity due to addition of more heat to said container.

2. In heating apparatus, the use of a pivotally mounted oscillatory piston for reciprocating gases for .the purpose of heattransfer.

3. A device for transferring heat from a heat-source to a receiver of heat, comprising an oscillating piston for reciprocating heat-carrying gases between said heat-source and said receiver.

4. Heating apparatus comprising a heating chamber, a memberv mounted for os- V cillation adjacent to said chamber, and

means for causing said member to force heating gases through said chamber in alternately opposite directions.

5. Heating apparatus comprising a heating chamber, an auxiliary chamber communicating with said heating chamber, and a member mounted for oscillation within said auxiliary chamber and adapted to force heating gases through said heating chamber in alternately opposite directions.

6. In a furnace, a gas-reciprocating mem ber mounted for oscillation between two end positions which are disposed at an angle of less than 360 degrees, walls enclosing the space through which said member oscillates, said walls having openings near the said end positions of said oscillating member, and a chamber connecting said openings.

7. In a furnace, a gas-reciprocating member mounted for oscillation between two end positions which are disposed at an angle of less than 360 degrees, walls enclosing the space through which said member oscillates, said walls having openings near the saidend positions of said oscillating member, a chamber connecting said openings,

and means for adding heat to the reciprocated gases.

8. In a furnace, a gas-reciprocating member pivotally mounted for oscillation between two end positions which are on opposite sides of the verticalplane including the pivotal axis of said member, whereby said member is able to swingas a natural pendulum.

9. In a furnace, an enclosure to be heated,

a gas-reciprocating piston mounted for oscillation below said enclosure, and a hori zontal arch disposed above said piston and below saidenclosure, said arch having ports I to permit reciprocation of the heating gases.

10. In a "furnace, an enclosure to be heated, a gas-reciprocating piston mounted for oscillation below said enclosure, a horizontal arch disposed above said piston and below said enclosure, said arch having ports to permit reciprocation of the heating gases, and a flexible seal for closing the space between said arch and the shaft of said piston. I

11. In heating a paratus, an enclosure to be heated, means or passing heating gases through portscommunicating with said enclosure, and means for injecting additional hot gases into said ports and for distributing said additional gases over the full depth m of each of said ports.

12. In heating apparatus, anenclosure to be heated, means for reciprocating heating gases through ports communicating with said enclosure, and means for injecting additional hot gases horizontally into each of soi 14. In a furnace 'for heating long objects to an even temperature, the combination of an elongated heating chamber, an auxiliary chamber of substantially the same length as said heating chamber and parallel thereto, and means extending through the full length of said auxiliary chamber for causing equal amounts of heating gases to pulsate back and forth through equal parts of said heating chamber, said gaspulsating means being arranged to move transversely within said auxiliary chamber.

15. In a furnace for heating long objects to an even temperature, the combination'of an elongated heating chamber, an auxiliary chamber of substantially the same length as said heating chamber and parallel thereto, means extending through the fulllength of said auxiliary chamber for causing equal amounts of heating gases to pulsate back and forth through equal parts of said heating chamber, said gaspulsating means being arranged to move transversely within said auxiliary chamber, and openings distributed over substantially the full length of said heating chamber and communicating with said auxiliary chamber.

16. In a furnace for heating long objects'to an even temperature, the combina-' tion of an elongated heating chamber, an auxiliary chamber of substantially the same length as said heating chamber and parallel thereto, means extending through the full length of said auxiliary chamber for causing equal amounts of heating gases to pulsate back and forth through equal parts of said heating chamber, said gas-pulsating means being arranged to move transversely within said auxiliary chamber, openings.

distributed over substantially the full length of said, heating chamber and communicating with said auxiliary chamber, and means for supplying heat over the full len h of said heating chamber.

1 In a furnace for heating long objects to an even temperature, the combination of an elongated heating chamber, an auxiliary chamber of substantially the same length as said heating chamber and parallel thereto, means extending through the full length of said auxiliary chamber for causing equal amounts of heating gases to pulsate back and forth through equal parts of said heating chamber, said gas-pulsating means being arranged to move transversely within said auxiliary chamber, openings distributed over substantially the full length of said heating chamber and communicating with said auxiliary chamber, means for supplying heat over the full length of said heating chamber, means for releasing surplus gases from said heating chamber, and means for adjusting the gas currents traversing said heating chamber.

18. Heating apparatus comprising a heating chamber, a heat-recuperating chamber, a hollow piston for reciprocating gases through said heating chamber, burners for heating said gases, and means for passing cooling air through said piston and for thereafter passing said air through said recuperating chamber and thence to said burners.

19. Heating apparatus comprising a heating chamber, an auxiliary chamber adjacent to said heating chamber and having a circularly curved wall opposite to said heating chamber, ports at opposite sides of said auxiliary chamber for connecting the said auxiliary chamber with the heating chamber, and a piston member mounted to oscillate within the said auxiliary chamber and between the said ports.

20. Heating apparatus comprising a heating chamber, an auxiliary chamber disposed below said heating chamber and communicating with the said heating chamber through ports arranged at the sides of said heating chamber, and an oscillating piston member mounted on a horizontal axis within said auxiliary chamber and between said ports.

21. Heating apparatus comprising a heating chamber, an auxiliary chamber disposed below said heating chamber, and communicating with said heating chamber through spaced series of ports arranged at opposite sides of said heating chamber and said auxiliary chamber, a shaft disposed between and parallel with said series of ports, a piston member carried by said shaft and means for oscillating said shaft.

22. Heating apparatus comprising a heating chamber, an auxiliary chamber disposed below said heating chamber and having a circularly curved lower wall, spaced series said series of ports, a hollow of ports connecting the said heating chamber and auxiliary chamber at the sides thereof, a horizontal hollow shaft within said auxiliary chamber and parallel with the iston member extending radially from sald shaft and adapted to sweep the space within said auxiliary chamber, means for oscillating the said shaft, and means for passing a coolin fluid through said hollow shaft and said hollow piston.

24. Heating apparatus comprising a heating chamber, an auxiliary chamber adjacent to said heating chamber, spaced ports connecting said chambers, an oscillating piston member disposed in said auxiliary chamber for establishing alternating currents ofgases in said chambers, burners for adding combustion gases to the circulated gases,

and adjustable openings for conducting gvaste gases away from said heating cham- 25; Heating apparatus comprising a heating chamber, an auxiliary chamber disposed below said heating chamber and having a circularly curved lower wall, spaced series of vertical ports connecting said chambers at opposite sides thereof, a hollow horizontal shaft in said auxiliary chamber and parallel to said series of supports, a hollow piston member extending radially from said shaft, means for oscillating said shaft, means for passing air through said hollow shaft and said hollow piston member, heatrecuperating chambers within the walls of I.

said heating chamber, burners disposed in communication with said Vertical ports, pipes for conducting the air from said hollow shaft through said recuperating chambers and for supplying the said air to the said burners, adjustable outlet ports connecting said heating chamber with said recuperating chambers, chimney pipes for conducting waste gases from said recuperating members, dampers for controlling said pipes, and means for automatically moving said dampers in response to the oscillating movement of said shaft to close the damper on the side of the furnace toward which said oscillating member is moving, and to 0 en the damper on the opposite side of the urnace.

26. The method of heating an elongated chamber that comprises reciprocating gas transversely through said chamber in equal volumes for e ual sections of its length, and adding heat 0 said reciprocating gas in equal amounts for equal sections of said len h.

27. The method of heating an elongated chamber that comprises reciprocating gas transversely through said chamber in equal volumes for equal sections of its length, add 10 ing heat to said reciprocating gas in equal amounts for equal sections of said length, and releasing surplus gases from said heating chamber.-

In testimony whereof I the said FRANZ l5 PUENING have hereunto set my hand.

FRANZ PUENING. 

